Security system monitoring services compete with each other for subscribers. As a result, it's not uncommon for these services to modify, replace, or add to the components of existing security system installations to acquire (i.e. hijack) subscribers from competitors. This is particularly disruptive since monitoring services often subsidize the costs of the security system components and initial installation.
Known monitored security systems often utilize a centralized architecture such that command and control of the system originates from the monitoring service. This architecture depends on the monitoring service maintaining a secure communications channel with the monitored installation. If this channel is hijacked by a competing service, then the competing service can also hijack the associated subscribers' accounts and associated income. This process is often referred to as a ‘man-in-the-middle’ cyber attack. Such practices often violate previous contracts between the monitoring service that paid for the initial installation and that installation's subscriber. Likewise, they are also assigned a high priority in the cyber threat models used in the design of the security systems.